Yes. If a criminal background check is done, the results will show the arrest and the pending charge. You have not been convicted, so it will not show a conviction.
The information provided is not advice but a legal perspective and you should schedule a consultation with the lawyer of your choice.
It depends on the criminal background company that provides (sells) your employer the report. Some reporting agencies will not report a pending charge unless its been disposed of (conviction, dismissal or plea down). However, regardless, if the employer uses the report to make an employment decision, it must first provide you with a copy of the report and a statement of rights BEFORE it decides to fire you. If it fails to do so, it has violated the Fair Credit Reporting Act (FCRA).